Happens every day, many times a day; there's nothing "wrong" with the routing.

Could literally be dozens of reasons why they took the route they did. Most frequent reason for non-direct routing is ATC restrictions / flow control, resulting in either having to route away from the congested area or accept a long delay. Most airlines will choose to route away from the troubles in order to suffer the smallet possible delay.

These re-routes happens on an all too frequent basis when the French or Greek ATCO goes on strike, and do they go on strike often!, resulting in severe flow restrictions over their airspace. On a flight from AMS to PMI we once routed into Germany, then down over Switzerland and Italy before hanging a right for PMI. Added a good hour to the flight, but the alternative was a 4 hour slot delay.

The other frequest reason is weather - you should have seen some of the routings they did earlier this week to avoid hurricane Phet over Oman and the IO.